On Cracks

On wrinkled penny-shaped cracks

A nominally at penny-shaped crack is subjected to a static loading. A perturbation method is developed for calculating the stress-intensity factors, based on an asymptotic analysis of the governing hypersingular boundary integral equation for the crack-opening displacement. Comparisons with known exact solutions for an inclined at elliptical crack and for a crack in the shape of a spherical cap...

Serration Effects on Interfacial Cracks

OSHA cracks down on sharps-safety violators.

www.nursingcenter.com THE OCCUPATIONAL Safety and Health Administration (OSHA) is cracking down on facilities that don’t comply with sharps-safety regulations. Two citations issued in 2003 show that health care facilities must fully comply with OSHA’s requirement to use safety-engineered sharp devices or pay a price. In 2001, OSHA revised the Bloodborne Pathogens Standard, strengthening its req...

Interface Cracks

-Properties of elastic solutions to interface crack problems are discussed in both the open formulation, in which the crack faces are assumed to be traction-free and interpenetration is permitted, and the unilateral formulation, where a contact zone is generally established adjacent to the crack tips. It is shown that if the contact zone is sufficiently small compared with the other dimensions ...

On the Resonances of Surface Breaking Cracks

The resonance phenomenon observed in Rayleigh wave scattering from surface-breaking cracks has been investigated using Freund's results on reflection of Rayleigh waves from an infinite crack edge. To model the crack as a section of acoustic waveguide, resonances are treated as standing waves in the length and depth directions. The model takes both faces of the crack into consideration, and this...